Meiourogonyaulax "mitra" (Dürr, 1987, p.74,77, figs.3a-b; fig.4, nos.3-6; fig.6, nos.1-3,5) Williams et al., 1993, p.55.

NOW Semicavidinium. Originally Meiourogonyaulax, subsequently Lithodinia, thirdly (and now) Semicavidinium. N.I.A.

Holotype: Dürr, 1987, fig.4, no.3; Dürr, 1988, pl.1, fig.5.
Age: mid Kimmeridgian.